Two Phaeophytin Type Analogues from Marine Sponge Dysidea sp.

A new compound named 13b (S )-hydroxy-17c-ethoxypheaophorbide a (2) together witha known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea sp.collected in South China sea. The structures were elucidated by spectroscopic analysis as well ascomparison with those reported in literatures.

Studies on the Steroids of Marine Sponge

Sterols are essential components of all eukaryotic cells and were the first group of marine sponge natural products used in the taxonomic characterization of marine sponges. Thus, in the past decade there has been an increasing interest in sterols of marine sponge, which has led to the discovery of a large number of novel compounds. The use of a variety of separation techniques has demonstrated the complexity of the sterol components of marine extracts, up to 50 sterols from one species of organism. However, the quantity of each sterol

A NEW CERAMIDE FROM THE MARINE SPONGE BIEMNA SP.

A new ceramide, biemnamide, was isolated from the marine sponge Biemne sp. collected from the South China Sea and Its structure was established by spectroscopic analysis.

Studies on the Steroids of Marine Sponge(Ⅳ)──Steroids from the Marine Sponge Biemna Sp

eported here is identification of a 7-en-sterol and a 5-en-sterol which containsa cyclopropane ring in its side chain and is separated from the South China Seasponge Biemna sp. . This leads to the isolation and identification of twelve sterols inthis marine sponge by using gas chromatography-mass spectrometry (GC-MS)analysis. The occurrence of 7-en-sterol and 5-en-sterol with a cyclopropane ring inits side chain from the south China Sea sponge was first reported here.

New bisabolane-type phenolic sesquiterpenoids from the marine sponge Plakortis simplex

Six new bisabolane-type phenolic sesquiterpenoids,including plakordiols A-D(1-4),(7 R,10 R)-hydroxycurcudiol(5)and(7 R,10 S)-hydroxycurcudiol(6)were isolated from the marine sponge Plakortis simplex collected from the South China Sea.Their structures were determined based on extensive analysis of spectroscopic data.Their configurations were assigned by coupling constant analysis,NOESY correlations,and the modified Mosher’s method.Furthermore,their cytotoxic and antibacterial activities were evaluated.

Molecular cloning of partial 14-3-3 genes in the marine sponge Hymeniacidon perleve and its role in differentiating infectious and non-infectious bacteria

Sponges （phylum Porifera） are the phylogenetically oldest metazoa and highly efficient filter feeders. In the marine ecosystem, they are unconditionally exposed to environmental stresses. Understanding the sponge-bacteria interaction is hence of both eco- logical and biological significance. This study investigated the specific interaction between the sponge Hymeniacidon perleve and the non-infectious bacteria, Escherichia coli and infectious bacteria, Vibrio spp. by measuring the 14-3-3 mRNA expression of H. perleve. Three partial cDNAs of 14-3-3 proteins and partial 18S RNA in H. perleve were cloned and sequenced. Using Re- verse-transcription real-time PCR, the 14-3-3 mRNA expression of H. perleve was examined when exposed to three common bacteria in aquatic water--E, coli and two Vibrio spp. for different time and dosages. H. perleve could efficiently remove E. coli from the water column without self-infection; however Vibrio at higher dosages infected H. perleve. When H. perleve was ex- posed to E. coli （1.1×10^7 CFU mL^-1）, V. anguillarum II （1.2×10^6 CFU mL^-1） and V. alginolyticus （3.6×10^5 CFU mL-1） for 6 h, the 14-3-3 mRNA expression in the V. anguillarum II and V. alginolyticus groups was down-regulated by 2.67- and 2.36-fold, respectively. The 14-3-3 mRNA expression in the E. coli group was not significantly different. However, no clear trend was ob- served on the 14-3-3 transcript levels of H. perleve in response to different doses of V. anguillarum II for different time. The re- sults demonstrated that infectious bacteria can be discriminated by 14-3-3 mRNA expression of sponge H. perleve.

Dysideanones F—G and dysiherbols D—E,unusual sesquiterpene quinones with rearranged skeletons from the marine sponge Dysidea avara

Four new sesquiterpene quinone meroterpenoids,dysideanones F—G(1—2)and dysiherbols D—E(3—4),were isolated from the marine sponge Dysidea avara collected from the South China Sea.The new structures were elucidated by extensive analysis of spectroscopic data including HR-MS and 1D and 2D NMR spectra,and their absolute configurations were assigned by single-crystal X-ray diffraction and ECD calculations.Anti-inflammatory evaluation showed that dysiherbols D—E(3—4)exhibited moderate inhibitory activity on TNF-α-induced NF-κB activation in human HEK-293T cells with IC_(50)values of 10.2 and 8.6μmol·L^(-1),respectively.

Fungal symbionts of marine sponges from Rameswaram,southern India:species composition and bioactive metabolites

Ten marine sponge species from Rameswaram,southern India were studied for their filamentous fungal symbionts.The results suggest that fungal symbionts of marine sponges are hyperdiverse.Genera such as Acremonium,Alternaria,Aspergillus,Cladosporium,Fusarium and Penicillium were frequently isolated;no true marine fungal species were present.Species of Aspergillus were dominant and co-dominant in all the sponges screened.The fungal isolates produced antialgal,antifungal,antioxidant,antibiotic,antiinsect metabolites.A few fungi produced acetylcholinesterase inhibitors.

Chemical and biological diversity of new natural products from marine sponges:a review(2009–2018)

Marine sponges are productive sources of bioactive secondary metabolites with over 200 new compounds isolated each year,contributing 23%of approved marine drugs so far.This review describes statistical research,structural diversity,and pharmacological activity of sponge derived new natural products from 2009 to 2018.Approximately 2762 new metabolites have been reported from 180 genera of sponges this decade,of which the main structural types are alkaloids and terpenoids,accounting for 50%of the total.More than half of new molecules showed biological activities including cytotoxic,antibacterial,antifungal,antiviral,anti-inflammatory,antioxidant,enzyme inhibition,and antimalarial activities.As summarized in this review,macrolides and peptides had higher proportions of new bioactive compounds in new compounds than other chemical classes.Every chemical class displayed cytotoxicity as the dominant activity.Alkaloids were the major contributors to antibacterial,antifungal,and antioxidant activities while steroids were primarily responsible for pest resistance activity.Alkaloids,terpenoids,and steroids displayed the most diverse biological activities.The statistic research of new compounds by published year,chemical class,sponge taxonomy,and biological activity are presented.Structural novelty and significant bioactivities of some representative compounds are highlighted.Marine sponges are rich sources of novel bioactive compounds and serve as animal hosts for microorganisms,highlighting the undisputed potential of sponges in the marine drugs research and development.

Antileishmanial potential of a marine sponge Haliclona oculata against experimental visceral leishmaniasis

Objective:To evaluate the antileishmanial activity of a marine spongeHaliclona oculata.Methods:The crude methanol extract was prepared from the freshly collected sponge and its three fractions were also prepared by maceration method.The antileishmanial activity of these extract and fractions was tested againstLeishmania donovani.Results:The antileishmanial activity was tested bothin vitroand in vivo.The crude methanol extract exerted almost complete inhibition of promastigotes(81.0%±6.9%)and 78.8%±5.2%inhibition of intracellular amastigotes at 100μg/mL with IC_(50)values of 29.5μg/mL and 40.6μg/mL,respectively.The treatment of 500 mg/kg(p.o.)of the crude methanol extract for 5 d for Leishmania donovani infected hamsters resulted in 78.35%±10.20%inhibition of intracellular amastigotes.At a lower dose(250 mg/kg),it exhibited poor efficacy.Among the fractions,highestin vitro(>75%)and in vivo(84.3%±10.2%)antileishmanial activity was observed in n-chloroform fraction with IC_(50)values of 54.2μg/mL and 61μg/mL against promastigotes and intracellular amastigotes,respectively.Hexane fraction andn-butanol(both insoluble and soluble)fractions were found inactivein vitroand in vivo.Conclusions:Our findings indicate that this marine sponge has the potential to provide new insight toward development of an effective antileishmanial agent and,hence,more exhaustive studies are needed for exploiting the vast marine resources of the world to combat the scourge of several parasitic diseases.

Antagonistic activity of marine sponges associated Actinobacteria

Objective:To focus on the isolation and preliminary characterization of marine sponges associated Actinobacteria particularly Streptomyces species and also their antagonistic activities against bacterial and fungal pathogens.Methods:The sponges were collected from Kovalam and Vizhinjam port of south-west coast of Kerala,India.Isolation of strains was carried out from sponge extracts using international Streptomyces project media.For preliminary identification of the strains,morphological(mycelial colouration,soluble pigments,melanoid pigmentation,spore morphology),nutritional uptake(carbon utilisation,amonoacids influence,sodium chloride tolerance),physiological(pH,temperature)and chemotaxonomical characterization were done.Antimicrobial studies were also carried out for the selected strains.Results:With the help of the spicule structures,the collected marine sponges were identified as Callyspongia diffusa,Mycale mytilorum,Tedania anhelans and Dysidea fragilis.Nearly 94 strains were primarily isolated from these sponges and further they were sub-cultured using international Streptomyces project media.The strains exhibited different mycelial colouration(aerial and substrate),soluble and melanoid pigmentations.The strains possessed three types of sporophore morphology namely rectus flexibilis,spiral and retinaculiaperti.Among the 94 isolates,seven exhibited antibacterial and antifungal activities with maximal zone of inhibition of 30 mm.The nutritional,physiological and chemotaxonomical characteristic study helped in the conventional identification of the seven strains and they all suggest that the strains to be grouped under the genus Streptomyces.Conclusions:The present study clearly helps in the preliminary identification of the isolates associated with marine sponges.Antagonistic activities prove the production of antimicrobial metabolites against the pathogens.Marine sponges associated Streptomyces are universally well known for their synthesis of many bioactive compounds such as antibiotics,enzymes,enzyme inhibitors and food grade pigments.They also have certain biotechnological applications like probiotics and single cell proteins.These marine Streptomyces bioactive metabolites can be the futuristic solution for the dreadful diseases.

Antifouling Activities of Marine Bacteria Associated with Sponge (Sigmadocia sp.)

The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.

Characterization of Biofilm Forming Marine Pseudoalteromonas spp

Biofilm forming bacteria are omnipresent in the marine environment.Pseudoalteromonas is one of the largest within the γ-proteobacteria class,and a member of marine bacteria.Species of Pseudoalteromonas are generally found in association with marine eukaryotes.In this work,we present the isolation and characterization of two strains forming biofilm on rock surface and associated with marine sponge.They were identified using 16SrDNA as Pseudoalteromonas prydzensis alex,and Pseudoalteromonas sp.alex.They showed the highest titer in biofilm formation quantified using the test tube method using crystal violet.

Cultivable yeasts associated with demosponges from Puerto Rico

Sponges are known for their symbiotic associations with bacteria and to a lesser extent with fungi.It has been argued that the association between fungi and sponges is not truly symbiotic,and fungal presence is incidental.Nevertheless,a vertically transmitted endosymbiotic yeast has been observed by transmission electron microscopy in sponges of the genus Chondrilla.Our work was focused on documenting the presence of yeasts associated with marine sponges from Puerto Rico.Sponge samples were taken from healthy mature colonies of Ircinia strobilina,Tedania ignis,and Chondrilla caribensis.A total of 36 yeast morphotypes were isolated and analysed by sequencing the nuclear ribosomal ITS region.Saccharomyces cerevisiae,was isolated from all the samples,comprising the first report of this yeast as a common inhabitant in marine sponges.Other yeasts isolated include the halophilic black yeast,Hortaea werneckii,and an unidentified species belongs to the Sporidiobolales(Basidiomycota).The high isolation frequency of S.cerevisiae from our sponge samples supports the possibility that Saccharomyces cerevisiae as an active member of the sponges’microbial community.

Two new diterpene alkaloids from the South China Sea Sponge Agelas aff. nemoechinata

Two new N-methyladenine-containing diterpenes,nemoechines F（l）and G（2）,were isolated from the South China Sea sponge Agelas aff.nemoechinata.The structures were assigned on the basis of spectroscopic date.Compound 2 showed weak activity against Jurkat cell lines with IC50 of 17.1 μmol/L

Three new non-brominated pyrrole alkaloids from the South China Sea sponge Agelas nakamurai

Three new non-brominated pyrrole alkaloids,nakamurines A-C（1-3） were isolated from the South China Sea sponge Agelas nakamurai.Their structures were elucidated on the basis of spectroscopic data.Compound 2 showed weak antimicrobial activity against Candida albicans with MIC of 60μg/mL.

5-Alkylpyrrole-2-carboxaldehyde derivatives from the Chinese sponge Mycale lissochela and their PTP1B inhibitory activities

Two new 5-alkylpyrrole-2-carboxaldehyde derivatives,mycalenitrile-15（1） and mycalenitrile-16（2）,along with five known related ones（3-7）,were isolated from the South China Sea sponge Mycale lissochela.The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR data with those reported in the literature.In bioassay,compounds 1 and 7 exhibited significant PTPIB（Protein-tyrosine phosphatase 1B,a recognized target for diabetes and obesity） inhibitory activities with IC（50） values of 8.6 and 3.1 μmoI/L,respectively.A preliminary SAR analysis of the isolated compounds with their PTP1 B inhibitory effects was described.

First total synthesis of a naturally occurring nucleoside disulfide:9-(5'-Deoxy-5'-thio-β-D-xylofuranosyl)adenine disulfide

A naturally occurring nucleoside disulfide, 9-（51-deoxy-5t-thio-β-D-xylofuranosyl）adenine disulfide, was first synthesized from o-xylose over 7 steps in 20% overall yield. The key step involved Vorbri.iggen glycosylation of silylated N6-benzoyladenine with xylose diacetate moiety.

Design, Synthesis and Antitumor Activity of Pyrrolopyrazinone-chalcone Hybrids

A series of pyrrolopyrazinone-chalcone hybrids（12a-12q） was designed,synthesized and screened for their antitumor activity against SKOV-3,A549 and HeLa cell lines in vitro.Compared with the pyrrolopyrazinone（10a） and 5-fluorouracil（5-FU）,nearly all the tested compounds showed significantly-improved antitumor activities.The most promising compounds 12e and 12k（IC50=0.25 and 0.88 μmol/L） respectively show activities of 123and 35 times that of compound 10a（IC50=30.74 μmol/L） against HeLa cell line.The result reveals that the presence of chalcone moiety is beneficial to their activity and selectivity.

An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp.

Objective:To investigate the in vivo efficacy and immune-modulatory potential of antagonistic strain,Streptomyces sp.MAPS15 isolated from marine sponge in Penaeus monodon(P.monodon).Methods:In this study,culture of Streptomyces sp.was incorporated into a commercial feed.P.monodon was orally administered with MAPS15 diet for a period of 21 days followed by a challenge experiment and survival rate was calculated.In addition,the effect of MAPS15 diet on immunological parameters of the haemolymph of P.monodon was also assessed.Results:The overall results of the study showed that survival performance was prominent in MAPS15 treated group when compared with un-treated control groups.That could pertain to the ability of MAPS15 to produce antibiotic compounds to suppress the growth of invading pathogens and thereby increase the disease resistance potency and survival rate.From the results of the immunological studies,it can be envisaged that the immune responses were generally more pronounced with MAPS15 diet treated group.Conclusions:Based on the overall findings,it could be inferred that the health of P.monodon is improved when they are fed with MAPS15 diet for a period of 21 days.